Readability Assessment of Package Leaflets of Biosimilars

Citing a lack of evidence regarding the determination of readability of biosimilar package leaflets sold in the European Union, authors for this cross-sectional, analytical study examined the readability and length of package leaflets of biosimilars downloaded from the European Medicines Agency (EMA) website.

“Taking into account the forecast growth in the market of biosimilars in the coming years, studying the readability of the package leaflets of biosimilars that are currently on the market is an important task,” they wrote.

The study sample included leaflets written in English for all biosimilars authorized by the EMA through August 31, 2017, an about which information could be obtained on the internet (n=35). Biosimilars included in the analysis included human growth hormones (n=2), insulins, granulocyte-colony stimulating factors (n=7), erythropoietins (n=5), low-molecular-weight heparins (n=2), parathyroid hormones, and monoclonal antibodies (n=12). The also examined six different sections of the package leaflet:

  • What X is and what it is used for
  • What you need to know before taking it
  • How to take/use
  • Possible side effects
  • How to store
  • Annex/handling instructions

The authors used two readability indices, the Flesch Index (FRE) and the Flesch-Kincaid Index (FKGL). The indices are inversely proportional, meaning that as a text becomes easier to read, its FKGL value decreases while its FRE increases. The authors did note that  all of the leaflets were more difficult to read than recommended for health-related texts, according to the FKGL (all the averages were >6). There were statistically significant differences between the leaflet sections in readability and in length, with the most difficult sections to understand being related to therapeutic indications and of possible side effects.

“Our results show that the package leaflets analyzed are longer than those of non-biological medicines, and of non-biosimilar biological medicines,” the authors wrote in their discussion. “Excessive information in the package leaflets does not meet the requirements of patients.”

This could potentially lead to harm down the road, the authors said.

The lack of readability that the package leaflets may exhibit could lead to not all patients reading them, and even to a certain degree of alarm in patients who do read them, which could reduce adherence to the treatment,” they wrote.

Study limitations included the patients not being contacted, which the authors explained could frame the current study as a first step in the identification of readability problems independent of study patients.

In their conclusion, the researchers did note that the European Commission has made an effort to contribute to proper package leaflet writing and issued guidelines in 2009. Biosimilar manufacturers have had time to make the necessary adjustments.

“To that end, it would always be possible, before publication of the package leaflet, to perform readability tests directly with the target patients (as is recommended in the guideline), and to apply readability formulas and assess the results as a prior step,” they wrote. “The competent organizations could be informed about package leaflets for authorized biosimilar medicines may not fulfil the function for which they were designed, which could have a negative effect on the use of the medicines by the user or patient.”

Read more at BMJ Open (https://bmjopen.bmj.com/content/9/1/e024837)